Sniffer dog Jazz can follow the scent of metal treated with a traceable DNA solution known as SelectaDNA.

She joined the Met Police in Romford on an operation last month to crack down on metal thieves.

Officers pulled over suspicious-looking vehicles for Jazz to get to work on.

While Jazz found no illegal activity on those searches, officers did find scrap dealers Ewall, of New Road, Rainham, to be operating without a licence.

The police then issued the dealers with a closure notice to shut for seven days so that Havering’s licensing officer could get a permanant closure order from the courts.

A total of 10 arrests were made throughout the operation, which also visited the Blackwall Tunnel, and nearly £5,000 of Thames water cable was recovered as well as 50kg of BT cable.

The head of the nationwide metal theft taskforce, Det Sup Alison Evans, said: “Metal thieves cause misery for the millions of people who live and work in the capital, whether by stealing from the rail network, power lines, telecommunications cable, or elsewhere, attacking our cultural heritage, and damaging the country’s infrastructure in the process.

“I welcome the success of this week’s activity and I would like to take this opportunity to thank all the officers, police forces, and industry partners who dedicated their time and energy to the preparation and implementation of this successful operation.”